Arterial disease can be considered one of the leading causes of mortality and morbidity in the United States, responsible for every third death or 2,500 deaths per day in the U.S. alone. Arterial disease may claims more lives each year than cancer, chronic lower respiratory diseases, accidents, and diabetes mellitus combined. As a result, clinical angiographic imaging (CAI) to diagnose vascular disease has increased by approximately 23% over the past 5 years. CAI may now be performed for approximately 1% of all Medicare patients.
Computed-Tomography Angiography (CTA) is one noninvasive imaging modality for evaluation of blood vessels and may be steadily replacing conventional invasive catheter-based angiography as the first-line diagnostic test for the evaluation of arterial disease. CTA can virtually replace all other alternative imaging modalities for some indications. CTA offers many advantages for the evaluation of arterial disease, including ease of use, excellent patient tolerance, rapid image acquisition, and outstanding morphological assessment of arterial stenoses, plaque, and mural irregularities.
However, one limitation of CTA is that CTA provides little to no information regarding the physiology of blood flow in a subject, such as flow velocity and turbulence. The absence of such blood flow data can lead to ambiguity regarding the functional relevance of the morphological findings provided by CTA. Furthermore, such ambiguity may result in a misinterpretation of the severity of arterial stenoses. Other available imaging methods that allow for blood flow assessments can also be limited because these methods either impose a relatively high risk of injury to the patient (e.g., conventional invasive catheter angiography) or are simply limited in scope (e.g., ultrasound). Furthermore, data obtained from exams that provide anatomical information can be difficult to combine with data obtain from exams that provide physiological information.
Accordingly, what is desired is to solve problems relating to using CTA and other imaging methods for the evaluation of arterial disease, some of which may be discussed herein. Additionally, what is desired is to reduce drawbacks using CTA for the evaluation of arterial disease, some of which may be discussed herein.